Japan is oddly "blessed" in some sense in that it doesn't really have that many natural resources. The only reason why imperialist powers showed any interest in the country in the first place was because they saw it as a useful stepping stone towards trade with/domination of China. The Chinese already had China, so they never had much of an interest in the place, and the only exception is of course the Mongols, the only people ever to have entertained serious thoughts of actually taking over the place, and, as aficionados of John Green will testify, the Mongols are always the exception. As such, Japan is oddly well-protected against imperialist powers, in that while western powers in the 19th century might very like the idea of having the Japanese be subservient to them and grant them full rights to their ports and even keeping military bases there, they're actually not going to be too keen to conquer the place and make it a proper colony.
My money is on that if Japan doesn't pull of a Meiji, it just becomes a backwater place that, while never modernizing politically nor industrializing, is neither ever properly conquered or colonized. Just a place that oddly enough gets by by, I dunno, leasing Nagasaki to the British or Americans or something of the sort.